backups: Add option to disable file revisioning

Also, add a BACKUP_EXCLUDE list which is a list of wildcard patterns which can
be used to exclude certain files from backup revisioning. This is useful for
temporary files such as those used for locks and undo space.

bin/bitpocket

@@ -18,6 +18,8 @@ LOCK_DIR="$TMP_DIR/lock"  # Use a lock directory for atomic locks. See the Bash
 SLOW_SYNC_TIME=10
 SLOW_SYNC_FILE="$TMP_DIR/slow"
 RSYNC_RSH="ssh"
+BACKUPS=true
+BACKUP_EXCLUDE=()
 
 # Default command-line options and such
 COMMANDS=()
@@ -90,6 +92,12 @@ function init {
 REMOTE_HOST=$1
 REMOTE_PATH="$2"
 
+## Enable file revisioning (>false< to disable)
+BACKUPS=true
+# These files are *not* revisioned. These use bash wildcard patterns instead of
+# rsync filter patterns
+BACKUP_EXCLUDE=( '*.tmp' '*.temp' '~\$*' '*.TMP' )
+
 ## SSH command with options for connecting to \$REMOTE
 # RSYNC_RSH="ssh -p 22 -i $DOT_DIR/id_rsa"
 
@@ -111,6 +119,21 @@ function log {
   tail -f "$DOT_DIR/log"
 }
 
+function should_backup() {
+  # Ensure backups are enabled, this is a file (not a dir or link), and that
+  # the file exists locally
+  [[ $BACKUPS && -f "$1" ]] || return 1
+
+  # Handle backup exclusions
+  for ex in "${BACKUP_EXCLUDE[@]}"
+  do
+    [[ "$1" == $ex ]]             && return 1
+    [[ $(basename "$1") == $ex ]] && return 1
+  done
+
+  return 0
+}
+
 function pull() {
   # Actual fetch
   # Pulling changes from server
@@ -138,7 +161,7 @@ function pull() {
     filename=$(sed "s:^\S*\s*::" <<< "$line" | sed 's:\d96:\\\`:g')
     if [[ "$line" =~ ^[ch\<\>][fd]|^\*deleting ]]; then
       operation=${line%% *}
-      if [[ -f "$filename" ]]; then
+      if should_backup "$filename"; then
         [[ -d "$DOT_DIR"/backups/$TIMESTAMP ]] \
           || mkdir -p "$DOT_DIR"/backups/$TIMESTAMP
         cp --parents -p --reflink=auto "$filename" \